What slicer can I use to process a .stp file format?

What slicer can process a .stp (STEP) file format?

Are we limited to the .stl file format?

STEP
STEP filenames normally end with .stp, from "STandard for the Exchange of Product model data"
STEP files are basically the gold standard for translating between different CAD applications.
People that do CAD for a living use STEP files because it is an ISO Standard

Quote
Dale Dunn
Another problem with .stl is the loss of precision due to faceting curved faces.
When the author only publishes the .stl file, part of the manufacturing process has already been determined,
That is, at the time of export, the precision of the faceted approximation for curved faces is set in stone.
Everybody else has to live with that, even if they would like to print with finer settings.

"CAD" files vs CAM files - a designer's plea
[forums.reprap.org]

RepRapFileFormat
[reprap.org]

ISO 10303-21, STEP-File
[en.wikipedia.org]

CAM Toolchains
[reprap.org]

File Formats
[reprap.org]

Toolpath generation software
[punkmanufacturing.com]

Slicers and user interfaces for 3D printers
[edutechwiki.unige.ch]

ICESL: A GPU ACCELERATED CSG MODELER AND SLICER
[code80.net]

Reprap host software
[reprap.org]

Edited 1 time(s). Last edit at 12/21/2013 11:50PM by A2.

Not sure if there is... you will have to STEP IN and then STL Out

Going from any CAD file to STL is no problem, it is when you only have an STL that makes it a lot of work if you want a more usable CAD file.

~

Autodesks Inventor (with free downloadable plug in) can turn a faceted STL into a solid (probably a nonmanifold part).

This is helpful for re-engineering the file into a CAD file.

FreeCAD will convert STEP to STL. Some information here: converting cad files to stl. I know some people swear by it, but in my experience FreeCAD is still pretty flaky.

Slic3r will supposedly read STL, AMF, and OBJ as input formats.

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MattMoses
FreeCAD will convert STEP to STL. Some information here: converting cad files to stl.

Way to complicate things, a script to do something that can already be done in the GUI. File --> Open, File --> Export.

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MattMoses
I know some people swear by it, but in my experience FreeCAD is still pretty flaky.

Please define flaky. Would you be a MacOS X user by any chance? Mac builds are a lot "flakier" than Linux and Windows versions because no one is sticking around to fix the Mac-specific bugs. FreeCAD being an open source project, it needs volunteers willing to contribute, but there are none using Macs.

FreeCAD runs superbly in Ubuntu and hardly crashes on me.

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MattMoses
Slic3r will supposedly read STL, AMF, and OBJ as input formats.

All mesh formats. What A2 wants is a slicer that will process a CAD file directly rather than a degraded mesh file.

Thanks, NormandC. Just to be clear, I like FreeCAD and I want to learn more about it. I say that it is "flaky in my experience" because the other day I had an assembly in IGS format that I wanted to view. I tried to use FreeCAD to open it, and got some jumbled mishmash of lines that was most definitely not a 3D model. At that point I just closed it and moved on because I didn't have time to mess with it.

Edit: I'm running windows

Edited 1 time(s). Last edit at 12/23/2013 01:11PM by MattMoses.

Were you able to view that IGS assembly in another CAD app?

Nope. FreeCAD was my only hope. (Unless there is another free IGS viewer out there. I didn't want to install any of the other free options I found because they looked suspicious.) But I get where you are going with this: I am not certain that the IGS file is OK.

To be fair, I guess I should mention that I've used FreeCAD to view STEP files before and it worked beautifully. This was a few months ago and I had forgotten about it until now. Funny how I remember the bad experience that happened recently instead of the good experience that happened months ago...

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NormandC
What A2 wants is a slicer that will process a CAD file directly rather than a degraded mesh file.

Correct, I want to save my CAD data file in the CAM .stp format,
and use a tool path generation software slicer,
G-code sending application, to print the CAM .stp file.

From my research I've found zero references to .stp formatted CAM data file being used with an Arduino microcontroller.
I presume that there is not an open source, or inexpensive .stp solution that an Arduino microcontroller is compatible with.

FreeCad uses the Open CASCADE engine, so I think in principle you could use that library to read a STEP file into an internal representation, then slice from that.

Well, that is a theory. I had a look at the STEP specification and it is pretty complex, in terms of the type of objects you can represent. I wanted to convert STEP models of components to a VRML format for KiCad, but I never managed to build the OpenCascade demo application.

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This is a complex subject, from what I understand FreeCAD uses the Open CasCade (OCC for short) STEP library which does not support the full STEP specifications. I believe what's needed is the STEP-NC control language that aims to replace the aging G-code.

There's been talk on the FreeCAD forum to switch from OCC's STEP library to a more complete one like STEPcode which is open source. But that will not happen soon.

bobc, did you try the "official" Open Cascade Technology or Open Cascade Community Edition (OCE)? The latter may be easier to build, at least on GNU/Linux.

Edited 1 time(s). Last edit at 12/23/2013 03:53PM by NormandC.

STEP-NC is a different kettle of fish. You would still need to slice the STEP model and produce a STEP-NC file containing toolpaths etc. I wouldn't like to try processing STEP-NC on an AVR Arduino, I think it would need an ARM with a decent amount of RAM. I'm not sure what the benefit of STEP-NC would be over GCode for printing, I am not sure that STEP-NC has any support for additive manufacturing anyway.

It was a while ago that I tried the OCT version, I know a lot of work has gone into the OCE version, which would be my starting point if trying again.

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First time reading about STEP-NC, this is my take away:

The advantage that STEP-NC holds for 3d printing is that it's platform independent.

With STEP-NC you could for example add a CMM (coordinate measuring machine) to your printer to conduct real time/in-process analysis of the part features.

STEP-NC allows you to make machine parameter adjustments based on the CMM measured features of the part being formed.

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A2
First time reading about STEP-NC, this is my take away:

The advantage that STEP-NC holds for 3d printing is that it's platform independent.

I don't think that is true, because STEP-NC currently is not defined for 3D printing. In future it might, although I have trouble seeing how that would work.

A conventional CNC will select tools at run time, e.g. drills, mills etc. But a printer typical has a fixed size nozzle, so how could you create a platform independent set of tool paths? The tool path has to be specific to a nozzle width. The only way to do that is for the printer to do it's own slicing from a model sent to it. In which case you just need the STEP model, not STEP-NC.

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With STEP-NC you could for example add a CMM (coordinate measuring machine) to your printer to conduct real time/in-process analysis of the part features.

STEP-NC allows you to make machine parameter adjustments based on the CMM measured features of the part being formed.

Are those things useful to have?

It's really not clear to me that the huge effort of implementing STEP-NC would bring any benefit to our typical 3D printers. Perhaps if you are running an industrial 3D printing production line then it would be useful. STEP-NC seems like a red herring.

Edited 1 time(s). Last edit at 12/24/2013 06:51AM by bobc.

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What is Open Source?
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Open Source in a nutshell: the Four Freedoms
CC BY-NC is not an Open Source license